Portion of a watch housing



FIG. 1 is a perspective view of the portion of a watch housing showing my new design; and,

FIG. 2 is a top view of the portion of a watch housing shown in FIG. 1.

The phantom line showing a portion of a watch in FIGS. 1-2 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a portion of a watch housing, as shown and described. 